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LOL... a real flash-back to the real meaning of putting a 'penny in the
fuse box'.....

Scott

On Mon, Jan 16, 2012 at 9:09 AM, George Brock-Nannestad <[log in to unmask]>wrote:

> From: Patent Tactics, George Brock-Nannestad
>
>
> Hi Richard,
>
> just a few comments on power supply and mains. In Denmark, the foremost
> source for amplifiers were batteries for High Tension and accumulators for
> the cathodes. So-called "battery eliminators", i.e. mains supply converted
> to
> suitable z.f. voltages, were an important item, and actually the major
> selling product of Bang & Olufsen when they were founded. Note my use of
> z.f.
> (zero frequency) for DC; it was to honour M.G. Scroggie of wireless fame
> who
> used this term because he thought that DC voltage was an abomination.
>
> Danish mains was DC (back to normal, again) for many years in many parts of
> the country, and the last place to give in to AC was Copenhagen; it only
> happened in the early 1960s. Gramophones had universal motors (some neat
> little things, but very good).
>
> Fuses and switches for DC have to have a much sturdier construction than
> for
> AC, because you really have to break an arc, whereas in AC there are two
> zero
> crossings of the current per cycle. This means that you do not need nearly
> as
> much cooling of the ionized gases to prevent re-ignition when the voltage
> goes up again. In the US, using 110 V for housing, the fuses and switches
> again have to be sturdier because the amperage rating is higher.
>
> In the UK, things are very interesting indeed. They do not have main
> circuit
> breaker fuses but fused outlets, or rather fuses in the plugs. And very
> many
> use ring mains, i.e. the circuit through the house has two parallel
> circuits
> going round and back to the main switch. This very much reduces the voltage
> drop on the in-house distribution. This is in sharp contrast to the star
> system used in Denmark, but I suppose you need it because the "normal" plug
> for kettles and the like has a built-in 13 A fuse, and you can have both
> your
> kettle and a toaster on at the same time. Not so in Denmark, you are
> limited
> to 10 A. A normal fuse has a time function that makes it blow instantly at
> 1.5 times the rating, and I suppose in one hour at 1.1 times the rating - I
> haven't checked since 1970.
>
> All the things you did not want to know about mains! And we have not even
> started on 3-phase.
>
> But Tom's photographs are beautiful!
>
> Best wishes,
>
>
> George
>
> ----------------------------------------
>
>
>
> > Hi, Tom,
> >
> > Wow, what memories this brings back. The only equipment that I have ever
> > owned that included these was a 1981 Canadian-market electric range. The
> > last house I had that used these was the old house I had in Canada from
> > 1981-1983, and a new service entrance and breaker panel were some of the
> > first things I did to the house. My old house in NY City lost these
> > about 1965--it was originally built in 1921 and had a single phase,
> > three wire service entrance with two of the 30 Amp fuses as mains. The
> > replacement had a two-pole 70 amp breaker. I upgraded the 100 amp to 200
> > amp in my 1984-2004 house in California and the house here came with a
> > 200 A breaker panel.
> >
> > These are not the best devices, but they certainly were pervasive. The
> > Fusetron fuses had diameters that were keyed to their ratings, so you
> > could not put in a different size once you screwed the adapter into the
> > "edison base" socket (same as a lamp). The adapters had anti-removal
> > pawls/springs so once the mod was done, it could not be easily undone.
> >
> > My 1921-built house had fuses in the neutrals as well as the hots!
> >
> > I'm mentioning this on-list because there are many non-North-American
> > list members who might have a bit of curiosity about how domestic sound
> > reproducing equipment received its power--these were the prevalent
> > protection devices from before the 1920s into the 1950s.
> >
> > Cheers,
> >
> > Richard
> >
> > On 2012-01-16 6:23 AM, Tom Fine wrote:
> > > All that you see here:
> > >
> > > http://beverage-digest.com/images/fuses/
> > >
> > > yours for the price of shipping.
> > >
> > > Not sure if anyone uses these things anymore or if there are old
> > > equipment installs that use them??
> > >
> > > Ping off-list if interested.
> > >
> > > - -- Tom Fine
> > >
> >
> > --
> > Richard L. Hess                   email: [log in to unmask]
> > Aurora, Ontario, Canada           (905) 713 6733     1-877-TAPE-FIX
> > http://www.richardhess.com/tape/contact.htm
> > Quality tape transfers -- even from hard-to-play tapes.
>



-- 
Best Regards,

Scott Phillips